CN102055706B - Mapping method of reference marks - Google Patents

Abstract

The invention discloses a mapping method of reference marks, comprising the following steps of: occupying the same subcarrier among pilot frequencies of reference marks corresponding to the same layer or the same port for code division multiplex in a first time slot of a subframe and carrying out time domain code division multiplex on adjacent or close OFDM (Orthogonal Frequency Division Multiplexing) marks corresponding to the subcarrier; occupying the same OFDM marks among reference marks corresponding to the same layer or the port for code division multiplex in a second time slot of the subframe and carrying out frequency domain code division multiplex on a plurality of adjacent or close subcarriers of the OFDM marks. With the method, the mapping influence caused by different numbers of configured OFDM marks can be eliminated.

Description

The mapping method of reference symbol

Technical field

The present invention relates to the communications field, in particular to a kind of mapping method of reference symbol.

Background technology

High-order multi-antenna technology is one of key technology of senior Long Term Evolution (LTE-A or LTE-Advanced, Long Term Evolution Advanced) system, in order to improve system transfer rate.In order to realize the channel quality measurement after introducing high-order multi-antenna technology and data demodulates, LTE-Advanced system respectively defines two class frequency pilot signs: data demodulates pilot tone (DMRS, Demodulation Reference Signal) and channel quality measurement pilot tone (CSI-RS, Channel State Information-Reference Signal), wherein, demodulation pilot frequency is used for the reference symbol of Physical Downlink Shared Channel (PDSCH, Physical Downlink SharedChannel) demodulation.The reference symbol that measurement pilot frequency is measured for CSI (channel stateinformation) indicates (CQI for channel quality, ChannelQuality Indicator), pre-coding matrix instruction (PMI, Precoding MatrixIndicator), the reporting of stratum's instruction information such as (RI, Rank Indicator).The structure of two class reference symbols may be used for supporting as multipoint cooperative (CoMP, CoordinatedMulti-Point), the new technical feature of the LTE-A such as spatial reuse.

In LTE, what adopt is that CRS carries out pilot measurement, namely all users use common pilot to carry out channel estimating, this public reference signal needs emitting side additional notifications receiving terminal to have employed which kind of pretreatment mode to the data of launching, expense is comparatively large simultaneously, in addition in MU-MIMO, because multiple UE is using identical CRS, the orthogonal of pilot tone cannot be realized, be therefore unable to estimate interference.

In LTE-A, in order to reduce the expense of pilot tone, witness mark symbol and demodulation reference mark are separately designed, JieDuHuaYu II Decoction reference signal and the identical pretreatment mode of data acquisition, demodulation reference mark is according to the available order information MAP reference symbol of dispatched users respective channels simultaneously, therefore can be adaptive according to order information adjustment expense, like this in the situation that order is lower, greatly expense can be reduced.Current LTE-A comprises the consistent viewpoint that demodulation reference mark design is formed:

Terminal is distinctive, the identical precoding processing of data acquisition of demodulation reference mark as corresponding in: particular terminal and dispatched users.

On-resource that only to exist only in network side (as eNodeB) is dispatched by transfer of data and layer.

-at network side, the reference symbol that different layers transmits is mutually orthogonal.

The design criterion of demodulation reference mark is to the expansion of the specific reference symbol of the terminal for beamforming transmission defined in R8 to multilayer.

In the LTE-A stage, two classes are mainly contained to the discussion of demodulation reference mark multiplex mode: CDM-T and CDM-F.So-called CDM-T (i.e. time domain code division multiplexing) refers to: carry out each layer of code division multiplexing in same sub-carrier location, and multiple OFDM adjacent or close in the time domain corresponding with this sub-carrier positions (Orthogonal FrequencyDivision Multiplexing, referred to as OFDM) on symbol, utilize orthogonal intersection spread spectrum to carry out code division multiplexing; So-called CDM-F (i.e. frequency domain code division multiplexing) refers to: the OFDM symbol that the time domain that the layer carrying out code division multiplexing takies is identical, and on adjacent or close multiple subcarriers of this OFDM symbol, utilizes orthogonal intersection spread spectrum to carry out code division multiplexing.

In 3GPP 58 meetings, have passed at present in normal cyclic prefix situation, to the baseline of the demodulation pilot frequency mapping method of the dual-layer beamforming (double-deck beamforming) of R9.As shown in Figure 1.

But still any conclusion is not shown to the demodulation pilot frequency method for designing in DwPTS and extended cyclic prefix subframe.In a tdd system, due to the existence of DwPTS, design and the normal sub-frame of its DMRS can there are differences, and therefore need other consideration.In normal CP situation, the length of DwPTS can be configured to 3,9,10,11,12 OFDM symbol.When being configured to 3 OFDM symbol, there is no the transmission of PDSCH data, the design of pilot tone pattern can be considered, be configured to 9,10,11, during 12 OFDM symbol, need the design rethinking DMRS.In expansion CP situation, the length of DwPTS can be configured to: 3,8,9,10 OFDM symbol, in like manner when being configured to 3 OFDM symbol, there is no the transmission of PDSCH data, the design of pilot tone pattern can be considered, be configured to 8, during 9,10 OFDM symbol, need the design rethinking DMRS.

If based on the method for designing of dual-layer, code division multiplexing process is carried out in time domain, i.e. CDM-T mode, and DwPTS is when being configured to different OFDM symbol, last several OFDM symbol is used for UpPTS and GP, therefore, under the OFDM symbol number different situations of DwPTS configuration, time domain can be affected and carry out code division multiplexing.As shown in Figure 2

In Fig. 2, time domain is still adopted to carry out the mode of CDM at second time slot (time slot 2), when DwPTS is configured to 10 OFDM symbol, the DMRS be positioned in 11 and 12 OFDM symbol will all be destroyed, and when being configured to 11 OFDM symbol, in pattern, DMRS on 11 12nd symbol is the code division multiplexing of time domain, after the 12nd symbol is struck off, DMRS on 11st symbol is still multiplexing between multiple layer, now cannot by pilot frequency information spreading code despreading being recovered to every layer, therefore the interference between generating layer, greatly decline making the performance of estimation.

It should be noted that, in normal cyclic prefix situation, corresponding first 7 of time slot 1 (the first time slot) (i.e. subframe 1st ~ 7) OFDM symbol, latter 7 of time slot 2 (the 2nd time slot) correspondence (i.e. subframe 8th ~ 14) OFDM symbol.In extended cyclic prefix, corresponding first 6 of time slot 1 (the first time slot) (i.e. subframe 1st ~ 6) OFDM symbol, latter 6 of time slot 2 (the 2nd time slot) correspondence (i.e. subframe 7th ~ 12) OFDM symbol.

The first grade design method is the mapping that suggestion is adopting the mode of CDM-F to carry out demodulation reference mark in addition, as shown in Figure 3, due in expansion CP situation, frequency selective fading is than serious in normal CP situation, therefore from simulation result, when the OFDM symbol number of DwPTS configuration is more, performance is poorer than CDM-T, but the different impact on mapping of the OFDM symbol number that more can adapt to configure.

Time more for the OFDM symbol number configured in correlation technique, capabilities map poor performance, and the problem that the different mapping projection of the OFDM symbol number that can not adapt to configure is rung, not yet propose effective solution at present.

Summary of the invention

When OFDM symbol number for configuration is more, capabilities map poor performance, and the problem of the OFDM symbol number difference mapping projection sound configured can not be adapted to and propose the present invention, for this reason, main purpose of the present invention is the mapping method providing a kind of reference symbol, to solve the problem one of at least.

To achieve these goals, according to an aspect of the present invention, a kind of mapping method of reference symbol is provided.

Mapping method according to reference symbol of the present invention comprises: at first time slot of subframe, carry out taking same subcarrier between the same layer of code division multiplexing or reference symbol pilot tone corresponding to same port, and carry out time domain code division multiplexing on the adjacent or close OFDM symbol that subcarrier is corresponding; At second time slot of subframe, carry out taking same OFDM symbol between the same layer of code division multiplexing or reference symbol corresponding to same port, and at adjacent or close multiple subcarriers enterprising line frequency territory code division multiplexing of OFDM symbol.

Preferably, in normal cyclic prefix situation, carry out time domain code division multiplexing at first time slot and carry out time division multiplexing in one of following OFDM symbol position: in first time slot the 3rd, 4 OFDM symbols; In first time slot the 6th, 7 OFDM symbols; In first time slot the 4th, 6 OFDM symbols carry out the code division multiplexing of time domain.

Preferably, in normal cyclic prefix situation, for second time slot, the method also comprises: when layer/port number is 1 or 2, with the 3rd or the 4th OFDM symbol of the second time slot, is wherein preferably the 3rd OFDM symbol; When layer/port number is greater than 2, with in the 3rd and the 4th OFDM symbol of the second time slot one of at least.

Preferably, in extended cyclic prefix situation, carrying out the multiplexing corresponding OFDM symbol position of time domain code division multiplexing at first time slot is: in first time slot the 3rd, 5 OFDM symbols, or in first time slot the 5th, 6 OFDM symbols carry out the code division multiplexing of time domain.

Preferably, in extended cyclic prefix situation, carry out at second time slot the 3rd OFDM symbol that multiplexing the used OFDM symbol of frequency domain code division multiplexing is second time slot.

Preferably, carrying out on the multiplexing OFDM symbol of time domain code division multiplexing, frequency domain position is the 1st, 6th and 11st subcarrier in current RB, or the 2nd, 6,10 subcarriers or Isosorbide-5-Nitraes, 7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, carrying out on the multiplexing OFDM symbol of frequency domain code division multiplexing, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, when design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.

To achieve these goals, according to an aspect of the present invention, a kind of mapping method of reference symbol is provided.

Mapping method according to reference symbol of the present invention comprises: when reference symbol is mapped in same time slot, when existence two adjacent not by control channel or transmission common reference symbol use OFDM symbol, and two OFDM symbols are used to demodulation reference mark when mapping, for on adjacent OFDM symbol, the mode multiplex mode of time domain code division multiplexing is adopted multiplexing.

Preferably, the method also comprises: in normal cyclic prefix situation, is the 3rd, 4 and/or 6 of subframe first time slot for time-domain position, 7 OFDM symbols, adopts the mode of time domain code division multiplexing multiplexing.

Preferably, the method also comprises: in extended cyclic prefix situation, is the 5th of subframe first time slot for time-domain position, 6 OFDM symbols, and adopts the mode of time domain code division multiplexing multiplexing; Or, be the 3rd, 5,6 OFDM symbols of subframe first time slot for time-domain position, and, the 3rd OFDM symbol adopts the mode of frequency domain code division multiplexing, on the 5th, 6 symbol, adopts the mode of time domain code division multiplexing multiplexing.

Preferably, the method also comprises: carrying out on the multiplexing OFDM symbol of time domain code division multiplexing, frequency domain position is the 1st, 6th and 11st subcarrier in current RB, or the 2nd, 6,10 subcarriers or Isosorbide-5-Nitrae, 7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, the method also comprises: carrying out on the multiplexing OFDM symbol of frequency domain code division multiplexing, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, the method also comprises: when design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.

Preferably, when reference symbol is mapped in same time slot, the method also comprises: when only having an OFDM symbol not by control channel or transmitting common reference symbol or UpPTS and GP use, and when being used to demodulation reference mark mapping, it is multiplexing that OFDM adopts the mode of frequency domain code division multiplexing.

Pass through the present invention, adopt first time slot in subframe, carry out taking same subcarrier between the same layer of code division multiplexing or reference symbol pilot tone corresponding to same port, and in the adjacent or close OFDM symbol that subcarrier is corresponding, carry out second time slot of time domain code division multiplexing in subframe, carry out taking same OFDM symbol between the same layer of code division multiplexing or reference symbol corresponding to same port, and at adjacent or close multiple subcarriers enterprising line frequency territory code division multiplexing of OFDM symbol, solve the OFDM symbol number of configuration more time, capabilities map poor performance, and the problem that the different mapping projection of the OFDM symbol number that can not adapt to configure is rung, and then reach the different mapping of OFDM symbol number that can adapt to configure and penetrate impact effect.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, and form a application's part, schematic description and description of the present invention, for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:

When Fig. 1 is the normal cyclic prefix according to correlation technique, the baseline pattern of normal sub-frames when number of layers is 2;

Demodulation reference mark mapping pattern when Fig. 2 is a kind of normal cyclic prefix based on CDM-T according to correlation technique in DwPTS;

Fig. 3 be according to correlation technique based on demodulation pilot frequency mapping pattern in DwPTS in the normal cyclic prefix of CDM-T;

Fig. 4 is the flow chart of the mapping method of reference symbol according to the embodiment of the present invention;

Fig. 5 is the flow chart of the mapping method according to the reference symbol in the normal cyclic prefix situation of the preferred embodiment of the present invention one;

Fig. 6 is the flow chart of the mapping method according to the reference symbol in the extended cyclic prefix situation of the preferred embodiment of the present invention one;

Fig. 7 is the flow chart of the mapping method according to the reference symbol in the normal cyclic prefix situation of the preferred embodiment of the present invention two;

Fig. 8 is the flow chart of the mapping method according to the reference symbol in the extended cyclic prefix situation of the preferred embodiment of the present invention two;

Fig. 9 is the flow chart taking the mapping method of the reference symbol in 4 OFDM symbol situations according to the preferred embodiment of the present invention two;

Figure 10 is the flow chart of the mapping method according to the reference symbol in the normal cyclic prefix situation of the preferred embodiment of the present invention three;

Figure 11 is the flow chart of the mapping method according to the reference symbol in the extended cyclic prefix situation of the preferred embodiment of the present invention three.

Embodiment

Hereinafter also describe the present invention in detail with reference to accompanying drawing in conjunction with the embodiments.It should be noted that, when not conflicting, the embodiment in the application and the feature in embodiment can combine mutually.

Fig. 4 is the flow chart of the mapping method of reference symbol according to the embodiment of the present invention, comprises the following steps:

Step S401, at first time slot of subframe, carries out taking same subcarrier between the same layer of code division multiplexing or reference symbol pilot tone corresponding to same port, and carry out time domain code division multiplexing in the adjacent or close OFDM symbol that subcarrier is corresponding;

Step S402, at second time slot of subframe, carries out taking same OFDM symbol between the same layer of code division multiplexing or reference symbol corresponding to same port, and at adjacent or close multiple subcarriers enterprising line frequency territory code division multiplexing of OFDM symbol.

This embodiment utilizes the demodulation reference mark mapping method of CDM-TF more can adapt to the change of the different OFDM symbol numbers of DwPTS configuration, first time slot adopts the mode of CDM-T multiplexing, ensure that the advantage of CDM-T in performance, and the second time slot adopts CDM-F, be more conducive to adapting to the DwPTS impact multiplexing on CDM when configuring different OFDM symbol number.Meanwhile, when considering the insertion of CSI-RS, can insert for CSI-RS reserves OFDM symbol.

Preferably, in normal cyclic prefix situation, carry out time domain code division multiplexing at first time slot and carry out time division multiplexing in one of following OFDM symbol position: in first time slot the 3rd, 4 OFDM symbol, or in first time slot the 6th, 7 OFDM symbol, or in first time slot the 4th, 6 OFDM symbol are carried out the code division multiplexing of time domain.

The preferred embodiment provides in normal cyclic prefix situation, carries out the specific embodiments of time domain code division multiplexing at first time slot.

Preferably, in normal cyclic prefix situation, for second time slot, said method also comprises: when layer/port number is 1 or 2, by the 3rd or the 4th OFDM symbol of the second time slot, is wherein preferably the 3rd OFDM symbol; When layer/port number is greater than 2, with in the 3rd and the 4th OFDM symbol of the second time slot one of at least.

The preferred embodiment provides in normal cyclic prefix situation, for the specific embodiments of second time slot.

Preferably, in extended cyclic prefix situation, carrying out the multiplexing corresponding OFDM symbol position of CDM-T at first time slot is: in first time slot the 3rd, 5 OFDM symbol, or in first time slot the 5th, 6 OFDM symbol is carried out the code division multiplexing of time domain.

The preferred embodiment provides in extended cyclic prefix situation, carries out the specific embodiments of time domain code division multiplexing at first time slot.

Preferably, in extended cyclic prefix situation, carry out at second time slot the 3rd OFDM symbol that multiplexing the used OFDM symbol of CDM-F is second time slot.

The preferred embodiment provides in extended cyclic prefix situation, carries out the multiplexing specific embodiments of CDM-F at second time slot.

Preferably, carrying out in the multiplexing OFDM symbol of CDM-T, frequency domain position is the 1st, 6th and 11st subcarrier in current RB, or the 2nd, 6,10 subcarriers or Isosorbide-5-Nitraes, 7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, carrying out in the multiplexing OFDM symbol of CDM-F, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, when design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.

According to another aspect of the present invention, additionally provide a kind of mapping method of reference symbol, the method comprises: when reference symbol is mapped in same time slot, when existence two adjacent not by control channel or transmission common reference symbol use OFDM symbol time, and two OFDM symbol are used to demodulation reference mark when mapping, for in adjacent OFDM symbol, the mode multiplex mode of CDM-T is adopted multiplexing.

This embodiment offers when reference symbol is mapped in same time slot, when the OFDM symbol do not used by control channel or transmission common reference symbol that existence two is adjacent, and two OFDM symbol are used to the mapping method of reference symbol when demodulation reference mark maps.

Preferably, above-mentioned method also comprises: in normal cyclic prefix situation, is the 3rd, 4 and/or 6 of subframe first time slot for time-domain position, 7 OFDM symbol, adopts the mode of CDM-T multiplexing.

The preferred embodiment provides in normal cyclic prefix situation, a kind of specific embodiments of the mapping method of reference symbol.

Preferably, above-mentioned method also comprises: in extended cyclic prefix situation, is the 5th of subframe first time slot for time-domain position, 6 OFDM symbol, and adopts the mode of CDM-T multiplexing;

Or, be the 3rd, 5,6 OFDM symbol of subframe first time slot for time-domain position, and, the 3rd OFDM symbol adopts the mode of CDM-F, on the 5th, 6 symbol, adopts the mode of CDM-T multiplexing.

The preferred embodiment provides in extended cyclic prefix situation, a kind of specific embodiments of the mapping method of reference symbol.

Preferably, above-mentioned method also comprises:

Carrying out in the multiplexing OFDM symbol of CDM-T, frequency domain position is the 1st, 6th and 11st subcarrier in current RB, or the 2nd, 6,10 subcarriers or Isosorbide-5-Nitraes, 7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, above-mentioned method also comprises:

Carrying out in the multiplexing OFDM symbol of CDM-F, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

Preferably, above-mentioned method also comprises:

When design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.

Preferably, when reference symbol is mapped in same time slot, above-mentioned method also comprises:

When only having an OFDM symbol not by control channel or transmitting common reference symbol or UpPTS and GP use, and when being used to demodulation reference mark mapping, it is multiplexing that OFDM adopts the mode of CDM-F.

The preferred embodiment provides the specific embodiments when reference symbol is mapped in same time slot.

The mapping method of reference symbol of the present invention comprises the content of following aspect:

1, a kind of in the DwPTS of LTE-A or in extended cyclic prefix, a kind of reference symbol mapping method (CDM-TF) of associating, comprise: layer/or the corresponding reference symbol of port of carrying out code division multiplexing, adopt the multiplex mode that time domain code division multiplexing and frequency domain code division multiplexing combine.

2, at first time slot, take the sub-carrier positions of same frequency domain between carrying out between reference symbol corresponding to each layer/port of code division multiplexing, and in the adjacent or close OFDM symbol that this subcarrier is corresponding, carry out code division multiplexing (namely adopt the mode of CDM-T multiplexing); In the OFDM symbol that the time domain carrying out taking between reference symbol corresponding to each layer/port of code division multiplexing is identical, and on adjacent or close multiple subcarriers of this OFDM symbol, utilize orthogonal intersection spread spectrum to carry out code division multiplexing (namely adopt the mode of CDM-F multiplexing).(DwPTS is configured to 10, during 11,12 OFDM symbol).

3, in normal cyclic prefix situation, carrying out the multiplexing corresponding OFDM symbol position of CDM-T at first time slot is, the 3rd, and 4 OFDM symbol, or the 6th, 7 OFDM symbol, or the 4th, 6 OFDM symbol are carried out the code division multiplexing of time domain.

In normal cyclic prefix situation, carrying out multiplexing the used OFDM symbol of CDM-F at second time slot is, when layer/port number is 1 or 2, by the 3rd or the 4th OFDM symbol of the second time slot, is wherein preferably the 3rd OFDM symbol; When layer/port number is greater than 2, by the 3rd and the 4th OFDM symbol of the second time slot or only use the 3rd or the 4th OFDM symbol.

4, in extended cyclic prefix situation, carrying out the multiplexing corresponding OFDM symbol position of CDM-T at first time slot is, the 3rd, and 5 OFDM symbol, or the 5th, 6 OFDM symbol are carried out the code division multiplexing of time domain.

5, in extended cyclic prefix situation, carrying out multiplexing the used OFDM symbol of CDM-F at second time slot is, the 3rd OFDM symbol of second time slot.

6, when reference symbol is mapped in same time slot or subframe, when existence two adjacent not by control channel or transmission common reference symbol use OFDM symbol time, and when being used to demodulation reference mark mapping, in adjacent OFDM symbol, adopt the mode mode that is multiplexing or CDM-F of CDM-T multiplexing; When adjacent position only has an OFDM symbol not used by control channel or transmission common reference symbol or UpPTS and GP, and be used to demodulation reference mark when mapping, adopt the mode of CDM-F multiplexing.(when DwPTS is configured to 9 OFDM symbol).

7, in normal cyclic prefix situation, time-domain position is the 3rd of the first time slot the, 4 and/or 6, and in 7 OFDM symbol, and adopt the mode of CDM-T multiplexing.

Or time-domain position is the the 4th and the 6th of the first time slot the, in 7 OFDM symbol, and on the 4th symbol, adopt the mode of CDM-F multiplexing, the 6th, 7 symbols adopt the mode of CDM-T multiplexing.

8, in extended cyclic prefix situation, time-domain position is the 5th of the first time slot the, 6 OFDM symbol, and adopts the mode of CDM-T multiplexing;

Or time-domain position is the 3rd of the first time slot the, 5,6 OFDM symbol, and, the 3rd OFDM symbol adopts the mode of CDM-F, on the 5th, 6 symbol, adopts the mode of CDM-T multiplexing.

9, carrying out in the multiplexing OFDM symbol of CDM-T, frequency domain position is the 1st, 6th and 11st subcarrier in current RB, or the 2nd, 6,10 subcarriers or Isosorbide-5-Nitraes, 7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB;

10, carrying out in the multiplexing OFDM symbol of CDM-F, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

The design of 11, above-mentioned reference symbol is applicable to the method for designing of demodulation reference mark and the method for designing of witness mark symbol simultaneously.

Wherein, when design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.

Illustrated based on demodulation reference mark mapping method of the present invention by specific embodiment under different layers number (i.e. rank number) configuring condition respectively.Embodiment is described based on demodulation reference mark, is also adapted to the design of witness mark symbol simultaneously.

The situation of preferred embodiment one: Rank 1 ~ 2

1, normal cyclic prefix situation.

When rank number is 2, based on the present invention in normal cyclic prefix situation when DwPTS is configured to 10,11, mapping method schematic diagram during 12 OFDM symbol is respectively as shown in 4-a, 4-b and 4-c in Fig. 5, in figure, be the 3rd OFDM symbol being mapped to the second time slot at the second time slot, when practical application, also can be mapped to the 4th OFDM symbol.In figure, DMRS pattern (when number of layers is 1 ~ 2) during different DwPTS configuration under normal CP, wherein Fig. 4-a, the corresponding DwPTS of 4-b, 4-c are configured to 10,11, pattern during 12 OFDM symbol, Fig. 4-d, 4-e correspondence is configured to pattern during 9 OFDM symbol.

In this embodiment, the OFDM symbol position corresponding diagram 4-a of the first Time Slot Occupancy is the 3rd, and 4 OFDM symbol are designated as x ₁={ x ₁₁, x ₁₂}={ 3,4}; Fig. 4-b is the 6th, and 7 OFDM symbol, are designated as x ₁={ x ₁₁, x ₁₂}={ 6,7}; Fig. 4-c is the 4th, and 6 OFDM symbol, are designated as x ₁={ x ₁₁, x ₁₂}={ 4,6}.At the first time slot, two OFDM symbol of same subcarrier time domain carry out code division multiplexing.In order to carry out Unify legislation to the time-domain position shown in Fig. 4-a, 4-b and 4-c, after use x ₁represent the OFDM symbol position of the first Time Slot Occupancy.

In Fig. 4-a, 4-b and 4-c, the frequency domain position that the first time slot is corresponding is the in a Resource Block the 1st, and 6,11 subcarriers, are designated as: y ₁={ y ₁₁, y ₁₂, y ₁₃}={ 1,6,11}, in practical application, also can be the 2nd, 6,10 subcarriers, now y ₁={ y ₁₁, y ₁₂, y ₁₃}={ 2,6,10}, or frequency-domain circular displacement can be carried out in above-mentioned position in a RB.Each carrier position y _1i, i=1,2,3, all correspond to x ₁the OFDM symbol comprised, carry out CDM-T multiplexing time, by orthogonal intersection at x ₁in the time-domain OFDM symbol that comprises carries out spread spectrum, and carry out code division multiplexing.

In several patterns shown in Fig. 4-a, 4-b and 4-c, the time-domain position of the second time slot is the 3rd OFDM symbol of the second time slot (the 10th OFDM symbol for this subframe), is designated as x ₂=3}, and in reality, also can with the 4th of a second time slot OFDM symbol (the 11st OFDM symbol for this subframe), now x ₂={ 4}.

At the second time slot, layer 1 and layer 2 adopt CDM-F to carry out code division multiplexing, and the frequency domain position of its correspondence is { [1,2]; [6,7]; [11,12] } individual subcarrier, be designated as y ₂={ [y ₂₁, y ₂₂]; [y ₂₃, y ₂₄]; [y ₂₅, y ₂₆]={ [1,2]; [6,7]; [11,12] }.At this time slot, code division multiplexing is at [y _2i, y _2i+1], i=1,2,3, two corresponding subcarriers are undertaken by orthogonal intersection.In practical application, frequency domain position also can be y ₂={ [y ₂₁, y ₂₂]; [y ₂₃, y ₂₄]; [y ₂₅, y ₂₆]={ [2,3]; [6,7]; [10,11] }, or y ₂the corresponding cyclic shift of sub-carrier positions in a RB.

In mapping mode described above, work as x ₂when corresponding OFDM symbol does not belong to the OFDM symbol of DwPTS configuration (when being used to UpPTS and GP, when being configured to 9 OFDM symbol corresponding to DwPTS), can in OFDM symbol that is remaining, that belong to DwPTS configuration, and the OFDM symbol being used to map demodulation reference mark carries out the mapping of demodulation reference mark, namely adopt and be configured to 10, the mapping mode of compatibility during 11,12 symbols.

Fig. 4-d and 4-e gives another mapping mode when DwPTS is configured to 9 OFDM symbol, equally also uses and the situation being configured to 10,11 or 12 OFDM symbol.Wherein Fig. 4-e adopts the mode of CDM-T, and shared OFDM symbol position is all positioned at the first time slot: be specially the 3rd of the first time slot the, 4,6,7 OFDM symbol, i.e. x ₁={ x ₁₁, x ₁₂, x ₁₃, x ₁₄}={ 3,4,6,7}; Corresponding frequency domain position is:

or

What Fig. 4-e adopted is the multiplex mode of CDM-F, and shared OFDM symbol position is equally all positioned at the first time slot, and concrete is the 4th of the first time slot, in 7 OFDM symbol, i.e. and x ₁={ x ₁₁, x ₁₂}={ 4,7}; Corresponding frequency domain position is:

or

In the mode that 4-d and 4-e provides, when the expense of demodulation reference mark is normal sub-frames 1/2, i.e. 6RE/RB, when maintaining 12RE/RB, the mode shown in Fig. 4-f can be adopted.In the mode shown in Fig. 4-f, demodulation reference mark is positioned at { 3,6,7} or { 4,6,7} OFDM symbol of the first time slot.In the 3rd or the 4th OFDM symbol, adopt the multiplex mode of CDM-F, the 6th, 7 symbol adopts the multiplex mode of CDM-T.Shared frequency domain position y ₁for:

2, extended cyclic prefix situation

DMRS pattern (when number of layers is 1 ~ 2) when different DwPTS configures under Fig. 6 shows and expands CP, wherein Fig. 5-a, 5-b, 5-c, 5-d is the pattern of DwPTS when being configured to 9 or 10 OFDM symbol, and Fig. 5-e and 5-f is pattern when being configured to 8 OFDM symbol.

Under 5-a wherein, 5-b give extended cyclic prefix situation, when DMRS expense is 12RE/RB, and DwPTS is configured to 9, the schematic diagram of demodulation reference mark mapping pattern during 10 OFDM symbol.With in normal CP situation mapping mode compared with, except time-domain position difference, other method is identical with 4-c with Fig. 4-b during normal CP.In extended cyclic prefix situation, when DMRS expense is 12RE/RB, the OFDM symbol position corresponding diagram 5-a of the first Time Slot Occupancy and 5-b is respectively x ₁={ x ₁₁, x ₁₂}={ 5,6} and x ₁={ x ₁₁, x ₁₂}={ 3,5}; Be x at the time-domain position of the second time slot ₂={ 3}.The mapping mode of frequency domain position and the first time slot with second time gap layer 1 layer 2 multiplex mode identical with in normal CP situation, no longer repeat here.

Fig. 5-c and 5-d gives the mapping pattern of the demodulation reference mark when DMRS expense is 16RE/RB.In this mapping mode, the first time slot is identical with 5-b with Fig. 5-a respectively with the OFDM symbol position shared by the second time slot.Difference is that density ratio 5-a and 5-b of frequency domain wants large.

Now, the frequency domain position of the first time slot is y ₁={ y ₁₁, y ₁₂, y ₁₃, y ₁₄}={ 2,5,8,11} or this group frequency domain position carry out circulation rotating in a RB.Be y at the frequency domain position of second time slot ₂={ [y ₂₁, y ₂₂]; [y ₂₃, y ₂₄]; [y ₂₅, y ₂₆]; [y ₂₇, y ₂₈]={ [1,2]; [4,5]; [7,8]; [10,11] } or this group frequency domain position in a RB, carry out cyclic shift.

When configuring DwPTS and being configured to 8 OFDM symbol, the OFDM symbol that last road maps DMRS can be removed, only use the DMRS position that the first time slot is corresponding.

Fig. 5-e and 5-f give other two kinds when DwPTS is configured to 8 OFDM symbol, the mapping method schematic diagram of demodulation reference mark, is equally also applicable to be configured to 9, the situation of 10 OFDM symbol.Wherein Fig. 5-e is the schematic diagram of 12RE/RB expense, and Fig. 5-f is the schematic diagram of 16RE/RB.In Fig. 5-e and Fig. 5-f, the OFDM symbol mapped shared by demodulation reference mark is all positioned at the first time slot, and corresponding time-domain position is the 3rd, 5th and 6th OFDM symbol of the first time slot, is denoted as x ₁={ x ₁₁, x ₁₂, x ₁₃}={ 3,5,6}, wherein in the 3rd OFDM symbol, layer 1 and layer 2 adopt the multiplex mode of CDM-F; 5th, 6 OFDM symbol adopts the multiplex mode of CDM-T.In mapping mode shown in Fig. 5-e, frequency domain position corresponding on each symbol is:

or the cyclic shift of described position in a Resource Block.

In the mapping mode that Fig. 5-f illustrates, frequency domain position corresponding on each symbol is:

Or the cyclic shift of described position in a Resource Block.

Preferred embodiment two: Rank 3 ~ 4

In rank 3 ~ 4 situation, the mapping of demodulation reference mark mainly based on rank 1 ~ 2 time expansion.A kind of mode still only carries out the mapping of demodulation reference mark in each subframe by 3 OFDM symbol.Another mode expands to 2 OFDM symbol at second time slot, in subframe, namely take 4 OFDM symbol positions.

1,3 OFDM symbol situations are taken

When using 3OFDM symbol, the mapping and multiplexing mode of the demodulation reference mark of rank 4 obtains based on embodiment 1 expansion, and the basis based on embodiment 1 is described for the explanation of this part.

2, normal cyclic prefix situation

Fig. 7 is DMRS pattern (when number of layers is 3 ~ 4), wherein Fig. 6-a, 6-b during different DwPTS configuration under showing normal CP, the corresponding DwPTS of 6-c is configured to 10,11, pattern during 12 OFDM symbol, Fig. 6-d, 6-e correspondence is configured to pattern during 9 OFDM symbol.

In Fig. 7,6-a, 6-b, 6-c give in normal cyclic prefix situation, when DwPTS is configured to 10,11, or during 12 OFDM symbol, maximum use 3 OFDM symbol map the schematic diagram of the mapping pattern of demodulation reference mark (DMRS:demodulation reference signal).Now based in rank2 normal cyclic prefix situation, mapping mode expansion when DwPTS is configured to 10,11 or 12 OFDM symbol obtains.Now, layer carries out code division multiplexing for 1 layer 2, and mapping mode when continuing to use previously described rank2 normal cyclic prefix and multiplex mode.Layer 3 and layer 4 carry out code division multiplexing.{ { 3,4} carries out frequency division multiplexing to layer for 1,2} and layer.

At the first time slot, carry out the layer of code division multiplexing: layer between 1,2} and layer { between 3,4}, in the OFDM symbol that time domain is adjacent or close, carry out code division multiplexing (CDM-T); At the second time slot, carry out the layer of code division multiplexing: layer between 1,2} and layer { between 3,4}, on the subcarrier that frequency domain is adjacent or close, carry out code division multiplexing (CDM-F).

Under layer 1 and layer 2 continue to use rank2 situation, DwPTS is configured to 10, during 11,12 OFDM symbol, corresponding to the method (with reference to figure 4-a, 4-b and 4-c) of normal cyclic prefix, here not repeating mapping method when layer 1 and layer 2.Only the mapping of layer 3 and layer 4 is described to ({ mapping position of 1,2} is with reference to describing with layer.

In this mode, layer { 3, in the time-domain position at the first time slot and the second time slot of 4} and normal cyclic prefix situation, rank 2 to go and DwPTS is configured to 10, during 11 or 12 OFDM symbol, { 1,2} is identical at the time-domain position that corresponding time slot (the first time slot, the second time slot) is corresponding for layer.Its frequency domain position, can with layer 1,2} for reference to being described, conveniently, here still definition layer 1,2} when rank2 the frequency domain position of the first time slot and the second time slot be y ₁and y ₂, and definition layer { frequency domain position that 3,4} is corresponding is yy ₁and yy ₂, then { frequency domain position that 3,4} is corresponding is layer

$\left\{\begin{array}{c}{\mathrm{yy}}_{1i}=\left\{\begin{array}{cc}{y}_{1i}+1& y_{1i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}\\ 1& y_{1i}=N_{\mathrm{RB}}^{\mathrm{subCarr}}\end{array}\right.\\ {\mathrm{yy}}_{2i}=\left\{\begin{array}{cc}{y}_{2i}+2& y_{2i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}-1\\ (y_{2i}+2)\mathrm{mod}{N}_{\mathrm{RB}}^{\mathrm{subCarr}}& y_{2i}>=N_{\mathrm{RB}}^{\mathrm{subCarr}}-1\end{array}\right.\end{array}\right.,---\left(1\right)$

In formula, x mod y represents that x is to y delivery, N _rB ^subCarrrepresent the number of sub carrier wave in a Physical Resource Block.I represents i-th frequency domain position in corresponding OFDM symbol.

Corresponding to the mapping position of this embodiment, be applicable to DwPTS and be configured to 10,11, demodulation reference mark mapping method during 12 OFDM symbol.When being configured to 9 OFDM symbol, a kind of mode is remove the OFDM symbol that last road maps DMRS, only uses the DMRS position that the first time slot is corresponding.

Based on embodiment at rank=2, in normal cyclic prefix situation, DwPTS corresponding to Fig. 4-d and 4-e signal is configured to mapping method during 9 OFDM symbol, Fig. 6-d and 6-e gives when rank=4, mapping method when DwPTS is configured to 9 OFDM symbol (is equally also applicable to be configured to 10,11, or the situation of 12 OFDM symbol).Now layer carries out code division multiplexing for 1 layer 2, and still continue to use previously described rank=2 and DwPTS is configured to 9 OFDM symbol time, mapping mode during normal cyclic prefix and multiplex mode (with reference to figure 4-d and 4-e).Layer 3 and layer 4 carry out code division multiplexing.{ { 3,4} carries out frequency division multiplexing to layer for 1,2} and layer.

The OFDM symbol position of the first time slot that layer 3 and layer 4 mapping pair are answered and the second time slot and layer 1, layer 2 is identical, repeats no more here.Under the mapping mode that Fig. 6-d illustrates, in the 3rd, 4 OFDM symbol, the frequency domain position that layer 3 and layer 4 map is identical with the frequency domain position of layer 2 in the 6th, 7 OFDM symbol with layer 1; Frequency domain position in the 6th, 7 OFDM symbol is identical with the position of layer 2 in the 3rd, 4 OFDM symbol with layer 1.Under the mapping mode that Fig. 6-e illustrates, layer 3 is identical with the frequency domain position of layer 2 in the 7th OFDM symbol with layer 1 with the frequency domain position that layer 4 maps on the 4th OFM symbol; Frequency domain position in the 7th OFDM symbol is identical with the frequency domain position of layer 2 in the 4th OFDM symbol with layer 1.

The mapping mode that Fig. 6-d and 6-e provides is the schematic diagram of 12RE/RB in expense, and when expense is 24RE/RB, mapping mode is as shown in Fig. 6-f.Now, { 1,2} carries out code division multiplexing to layer, and { 3,4} carries out code division multiplexing to layer, adopts frequency division multiplexing between two groups.Wherein, the time-domain position shared by each layer is { 3,6,7} OFDM symbol or { 4,6,7} OFDM symbol.Shared frequency domain position is:

Layer 1,2}:

Layer 3,4}:

Above-mentioned frequency domain position also can carry out cyclic shift at the frequency domain of a Physical Resource Block.

3, extended cyclic prefix situation

Fig. 8 gives in extended cyclic prefix situation, when DwPTS is configured to 9 or 10 OFDM symbol, and maximum use 3 OFDM symbol map the schematic diagram of the pattern of demodulation reference mark (DMRS:demodulation reference signal).DMRS pattern (when number of layers is 3 ~ 4) when different DwPTS configures under Fig. 8 shows and expands CP, wherein Fig. 7-a, the corresponding DwPTS of 7-b, 7-c, 7-d are configured to 10, pattern during 11,12 OFDM symbol, Fig. 7-e, 7-f correspondence is configured to pattern during 9 OFDM symbol.Schematic diagram 7-a and 7-b is the expansion based on 5-a and 5-b during extended cyclic prefix, and expense is 24RE.With similar during normal cyclic prefix, now, layer carries out code division multiplexing for 1 layer 2, and mapping mode when continuing to use the rank=2 extended cyclic prefix of embodiment 1 description.Layer 3 and layer 4 carry out code division multiplexing.{ { 3,4} carries out frequency division multiplexing to layer for 1,2} and layer.

In extended cyclic prefix situation, multiplex mode with the same during normal cyclic prefix, and layer in the time-domain position at the first time slot and the second time slot of 3,4} and extended cyclic prefix situation during rank2 layer { 1,2} is identical at the time-domain position that corresponding time slot is corresponding.The defining method of its frequency domain position is also identical with during normal cyclic prefix, and still { frequency domain position that 3,4} is corresponding is yy to definition layer ₁and yy ₂, when defining extended cyclic prefix, { frequency domain position of 1,2} the first time slot and second time slot when rank2 is y to layer simultaneously ₁and y ₂, then { frequency domain position that 3,4} is corresponding can pass through formula (1) and can obtain layer equally, namely

$\left\{\begin{array}{c}{\mathrm{yy}}_{1i}=\left\{\begin{array}{cc}{y}_{1i}+1& y_{1i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}\\ 1& y_{1i}=N_{\mathrm{RB}}^{\mathrm{subCarr}}\end{array}\right.\\ {\mathrm{yy}}_{2i}=\left\{\begin{array}{cc}{y}_{2i}+2& y_{2i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}-1\\ (y_{2i}+2)\mathrm{mod}{N}_{\mathrm{RB}}^{\mathrm{subCarr}}& y_{2i}>=N_{\mathrm{RB}}^{\mathrm{subCarr}}-1\end{array}\right.\end{array}\right.,$

Wherein x mod y represents that x is to y delivery.

Fig. 7-c and 7-d gives in extended cyclic prefix situation, mapping mode schematic diagram when a kind of expense is 28 Resource Units (RE), in this mode, at the second time slot, { mapping mode of 3,4} continues to use mapping mode when above-mentioned expense is 24RE to layer.The mapping of the first time slot is the expansion of the first time slot mapping mode when expense is 16RE in extended cyclic prefix rank2 situation, now layer 1,2} with in rank2 extended cyclic prefix situation, when demodulation reference mark expense is 16RE, { mapping mode of 1,2} is identical for layer.Still { 1,2} is y in the position of the first time slot to definition layer _1i, { 3,4} is yy in the mapping position of the first time slot to definition layer ₁, its value is:

${\mathrm{yy}}_{1i}=\left\{\begin{array}{cc}{y}_{1i}+1& y_{1i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}\\ 1& y_{1i}=N_{\mathrm{RB}}^{\mathrm{subCarr}}\end{array}\right.$

Corresponding to the mapping position of this embodiment, be applicable to DwPTS and be configured to 9, demodulation reference mark mapping method during 10 OFDM symbol.When being configured to 8 OFDM symbol, can removing based on aforesaid way the OFDM symbol that last road maps DMRS, only using the DMRS position that the first time slot is corresponding.

Fig. 7-e and 7-f give other two kinds when DwPTS is configured to 8 OFDM symbol, the mapping method schematic diagram of demodulation reference mark, equally also be applicable to configuration during 9 or 10 OFDM symbol, wherein Fig. 7-e is the schematic diagram of 24RE/RB expense, and Fig. 7-f is the schematic diagram of 28RE/RB.In Fig. 7-e and Fig. 7-f, the OFDM symbol mapped shared by demodulation reference mark is all positioned at the first time slot, and corresponding time-domain position is the 3rd, 5th and 6th OFDM symbol of the first time slot, is denoted as x ₁={ x ₁₁, x ₁₂, x ₁₃}={ 3,5,6}, wherein in the 3rd OFDM symbol, layer 1 and layer 2 adopt the multiplex mode of CDM-F; 5th, 6 OFDM symbol adopts the multiplex mode of CDM-T.Layer 3 and layer 4 and layer 1 and layer 2, in OFDM symbol 3 and OFDM symbol 5, adopt identical multiplex mode on 6.

In mapping mode shown in Fig. 7-e, the frequency domain position that layer 1 and layer 2 are corresponding on each symbol is:

or the cyclic shift of described position in a Resource Block.

Layer 3 and the mapping position of layer 4 in each OFDM symbol are denoted as yy ₁

In formula, i represents i-th frequency domain position in corresponding OFDM symbol, in the 3rd OFDM symbol, and 1≤i≤6,1≤i≤3 in the 5th, 6 OFDM symbol.

In the mapping mode that Fig. 7-f illustrates, the frequency domain position that layer 1 and layer 2 are corresponding on each symbol is:

or the cyclic shift of described position in a Resource Block.

Layer 3 and the mapping position of layer 4 in each OFDM symbol will be denoted as yy ₁

In formula, i represents i-th frequency domain position in corresponding OFDM symbol, in the 3rd OFDM symbol, and 1≤i≤6,1≤i≤4 in the 5th, 6 OFDM symbol.

4,4 OFDM symbol situations are taken

When rank4, when employing 4 OFDM symbol, based on the multiplexing method of CDM-TF described in the invention, be mainly applicable to the situation of normal cyclic prefix.A kind of mapping pattern schematic diagram based on this thought is given in Fig. 9, when number of layers is 3 ~ 4, and when taking 4 OFDM symbol, under normal CP, DwPTS is configured to the demodulation reference mark mapping pattern schematic diagram of 11 or 12 OFDM symbol, being configured to 10 is remove last 1 tunnel, when being configured to 9, remove last 2 tunnels.Wherein Fig. 8-a, 8-b and 8-c respectively illustrate the situation of different time domain position.From schematic diagram, between each layer carrying out code division multiplexing at the first time slot time adjacent or close OFDM symbol corresponding to same subcarrier on carry out code division multiplexing; And the second time slot carry out code division multiplexing layer between be in identical OFDM symbol, two adjacent or close subcarriers carry out code division multiplexing.

In each schematic diagram shown in Fig. 9, the position of the second time slot is the 3rd of the second time slot the, and 4 OFDM symbol (i.e. the 10th and the 11st OFDM symbol of present sub-frame), are denoted as x ₂={ 3,4}; In the figure of wherein 8-a signal, the time-domain position of the first Time Slot Occupancy is the 4th and the 6th OFDM symbol x of this time slot ₁={ x ₁₁, x ₁₂}={ 4,6}; The time-domain position of the first Time Slot Occupancy in Fig. 8-b is the 3rd of this time slot the, and 4 OFDM symbol, are denoted as x ₁={ x ₁₁, x ₁₂}={ 3,4}; The time-domain position of the first Time Slot Occupancy in Fig. 8-c is the 6th of this time slot the, and 7 OFDM symbol, are denoted as x ₁={ x ₁₁, x ₁₂}={ 6,7};

The frequency domain position provided in several schematic diagrames in Fig. 9 is identical, and correspondence often plants situation, and { 1,2} takies identical frequency domain position to layer, and carries out code division multiplexing; { 3,4} takies identical position to layer, and carries out code division multiplexing; { 1,2} and layer { are undertaken multiplexing by the mode of frequency division between 3,4} layer.

{ 1,2} is the 1st, 6,11 subcarriers in a Resource Block at the frequency domain position of the first Time Slot Occupancy, is designated as: y in its middle level ₁={ y ₁₁, y ₁₂, y ₁₃}={ 1,6,11}; Or the 2nd, 6,10 subcarriers, i.e. y ₁={ y ₁₁, y ₁₂, y ₁₃}={ 2,6,10}; Or frequency-domain circular displacement is carried out in above-mentioned position in a RB.Each carrier position y _1i, i=1,2,3, all correspond to x ₁the OFDM symbol comprised, carry out CDM-T multiplexing time, by orthogonal intersection at x ₁in the time-domain OFDM symbol that comprises carries out spread spectrum, and carry out code division multiplexing.Due to layer, { 1,2} is adopt the multiplex mode of CDM-F at the second time slot, and the frequency domain position of its correspondence is: [1,2] of a Resource Block in this time slot the 3rd OFDM symbol, [11,12] individual subcarrier y ₂={ [y ₂₁, y ₂₂], [y ₂₃, y ₂₄]={ [1,2], [11,12] } or y ₂={ [y ₂₁, y ₂₂], [y ₂₃, y ₂₄]={ [2,3], [10,11] }; In this time slot the 4th OFDM symbol, [6,7] individual subcarrier of a Resource Block, is denoted as y ₃={ [y ₃₁, y ₃₂]={ [6,7] }; Wherein this time slot, the frequency domain position in the 3rd and the 4th OFDM symbol can exchange.

Layer 3,4} the first time slot frequency domain position can with layer 1,2} be with reference to description, at the first time slot, { time-domain position of 3,4} is for using yy for layer ₁represent, then its corresponding frequency domain position is

${\mathrm{yy}}_{1i}=\left\{\begin{array}{cc}{y}_{1i}+1& y_{1i}<N_{\mathrm{RB}}^{\mathrm{subCarr}}\\ 1& y_{1i}=N_{\mathrm{RB}}^{\mathrm{subCarr}}\end{array}\right.$

In the 3rd OFDM symbol, { { position of 1,2} in the 4th OFDM symbol is identical for the frequency domain position of 3,4} and layer for layer; In the 4th OFDM symbol, { { position of 1,2} in the 3rd OFDM symbol is identical for the frequency domain position of 3,4} and layer for layer.

Fig. 8-d gives one and adopts CDM-F code division multiplexing method completely, and { adopt the code division multiplexing of frequency domain between 1,2}, { 3,4} adopts the code division multiplexing of frequency domain to layer in its middle level.Layer the time-domain position shared by 1,2} is the 6th and the 10th OFDM symbol or the 3rd of a subframe, and the 10th OFDM symbol, be denoted as x={x ₁, x ₂}={ 6,10} or 3,10} OFDM symbol, the frequency domain position of its correspondence is [1,2] of corresponding time-domain OFDM symbol, [6,7], [11,12] individual subcarrier or [2,3], [6,7], and [10,11] individual subcarrier, is denoted as:

Y={ [y ₁, y ₂], [y ₃, y ₄], [y ₅, y ₆]={ [1,2], [6,7], [11,12] } or { [2,3], [6,7], [10,11] }

Layer [3,4] and layer 1,2 take identical frequency domain position or the cyclic shift of the corresponding frequency domain position of layer 1,2 in a RB, and its frequency domain position is xx=x+1, and wherein x is layer 1, the OFDM symbol position shared by layer 2.

As can be seen from the various modes illustrated in Fig. 9, in a Resource Block, the density distribution between each layer of the second time slot is uneven, for this reason, on adjacent Resource Block, can rotate the position of the second time slot.Namely the Resource Block that hypothesis two is adjacent is designated as Resource Block k and Resource Block k+1 respectively, then, on the second time slot, the frequency domain position of Resource Block k+1 each layer in the 4th OFDM symbol is identical with the position of Resource Block k in the 3rd OFDM symbol; And the frequency domain position of Resource Block k+1 each layer in the 3rd OFDM symbol is identical with the position of Resource Block k in the 4th OFDM symbol.Thus ensure from whole system, the even density of each layer.

Preferred embodiment three: rank5 ~ 8 situation

As rank > 5, its application scenarios should be mainly low speed and selectivity of channel frequency declines in not serious scene, and the situation of PRB binding (PRB bundling) is considered in the mapping of suggestion demodulation reference mark at this moment.

So-called PRB bundling refers to improve precision of channel estimation, and the design of demodulation reference mark allows terminal when carrying out channel estimating, by continuous 2 or multiple PRB continue joint channel estimation, thus improves precision of channel estimation.

When demodulation reference mark designs, PRB bundling mainly refers to that the frequency domain density distribution of the demodulation reference mark in order to make every layer is even.Concrete a kind of implementation method is that 8 layers are divided into 2 groups, often organizes 4 layers, and on adjacent material resources block (PRB) k and k+1, the frequency domain position of group 1 on a kth PRB is identical with the frequency domain position of group 2 on k+1 PRB; Then the frequency domain position of group 2 on a kth PRB is identical with the frequency domain position of group 1 on k+1 PRB.

For convenience of description, the mapping mode of demodulation reference mark is only described according to a PRB after.On adjacent PRB, obtain the frequency domain position of each layer on adjacent PRB according to mapping mode during above-mentioned PRB bundling.

1, normal cyclic prefix situation

Figure 10 DMRS pattern (when number of layers is 5 ~ 8) during different DwPTS configuration under showing normal CP, wherein the corresponding DwPTS of Fig. 9-a, 9-b is configured to 11, pattern during 12 OFDM symbol, the correspondence of Fig. 9-c, 9-d is configured to 10,11, pattern during 12 OFDM symbol, Fig. 9-e, 9-f correspondence is configured to pattern during 9 OFDM symbol.It is 24RE that 9-a and 9-b wherein gives overhead, DwPTS is configured to mapping pattern during 11 or 12 OFDM symbol, in Fig. 9-a, at the first time slot, the each layer carrying out code division multiplexing adopts the multiplex mode of CDM-T, at the second time slot, each layer carrying out code division multiplexing adopts the multiplex mode of CDM-F.In figure, between 8 layers, two two-layerly carry out code division multiplexing.In the present embodiment, by { 1,2,5,6} is divided into 1 group, and { 3,4,7,8} are divided into one group to layer.Its middle level 1, layer 2 carries out code division multiplexing, layer 3, and layer 4 carries out code division multiplexing, layer 5, and layer 6 carries out code division multiplexing, layer 7, and layer 2 carries out code division multiplexing 8, in practical application, is not limited to this packet mode.

Each layer is x in the first time slot in the time-domain OFDM symbol position shared by the first time slot ₁={ 3,4} or { OFDM symbol corresponding to 6,7}, the OFDM symbol position of each layer shared by the second time slot is x ₁={ the OFDM symbol that 3,4} is corresponding.For ease of describing, be designated as g respectively by 4 groups that carry out code division multiplexing ₁, g ₂, g ₃, g ₄, wherein g _irepresent i-th group of layer carrying out code division multiplexing.Simultaneously by g ₁, g ₂be classified as one and organize G1 greatly; g ₃, g ₄be classified as and organize G2 greatly.The time-domain position shared by each group and the frequency domain position that then carry out code division multiplexing are

g ₁：

g ₂：

g ₃：

g ₄：

When carrying out PRB bundling, in adjacent kth and kth+1 PRB, g in G1 ₁g in time-frequency domain position corresponding to a kth PRB and G2 ₃the time-frequency domain position of the correspondence of each comfortable kth+1 is obtained at the time-frequency domain position phase double replacement that a kth PRB is corresponding; G in G1 ₂g in time-frequency domain position corresponding to a kth PRB and G2 ₄the time-frequency domain position of the correspondence of each comfortable kth+1 is obtained at the time-frequency domain position phase double replacement that a kth PRB is corresponding; Based in the pattern that Fig. 9-a provides, at the second time slot, g ₃and g ₄corresponding time-frequency domain position also can be

g ₃：

g ₄：

It is 24RE, DwPTS mapping pattern when being configured to 11 or 12 OFDM symbol that Fig. 9-b gives another overhead.In mode shown in figure, adopt the multiplex mode of CDM-T in whole subframe, and by carrying out code division multiplexing in different OFDM symbol on same carrier wave.In figure, every 4 layers carry out code division multiplexing, can { 1,2,5,7} is divided into one group to carry out code division multiplexing, is designated as g by layer ₁; { 3,4,6,8} is divided into one group to carry out code division multiplexing to layer, is designated as g ₂, in practical application, also can be other dividing mode.Here only illustrate as example, group g ₁in the distinct symbols of each layer in whole subframe on carry out CDM-T code division multiplexing, group g ₂in each layer carry out code division multiplexing by the mode of CDM-T.The each group of time-frequency domain position taken is (here with whole sub-frame description OFDM symbol relative position):

g ₁：

g ₂：

Fig. 9-i gives a kind of DMRS mapping pattern when adopting CDM-T completely, and overhead is still 24 RE, DwPTS mapping pattern when being configured to 11 or 12 OFDM symbol.In this mode, all layers are equally divided into 4 groups, in figure, can { 1,2} be divided into one group to carry out code division multiplexing, is designated as g by layer ₁; { 3,4} is divided into one group to carry out code division multiplexing to layer, is designated as g ₂, { 5,7} is divided into one group to carry out code division multiplexing, is designated as g layer by layer ₃; { 5,7} is divided into one group to carry out code division multiplexing, is designated as g layer by layer ₄.In practical application, also can be other dividing mode, the time-frequency domain position of each group correspondence be

g ₁：

g ₂：

g ₃：

g ₄：

Wherein frequency domain position also can be the cyclic shift of above-mentioned value in a RB on frequency domain.

Fig. 9-c and Fig. 9-d, it is 24RE, DwPTS mapping pattern when being configured to 10 OFDM symbol that 9-g, 9-h sets forth overhead, and pattern is suitable for 11 equally, configuration during 12 OFDM.Wherein, Fig. 9-c be based on 9-a signal be configured to 11 or 12 OFDM symbol time, on the basis of described scheme, directly remove last road, concrete mapping position can be obtained to last road is directly removed on the basis of the mode described by 9-a based on above-mentioned, concurrent multiplexing mode, with reference to the description to 9-a, repeats no more here.

In Fig. 9-d, the multiplex mode of each layer, identical multiplex mode is adopted with the mode described in 9-b above, namely every 4 layers are one group, mode by CDM-T in 4 different OFDM symbol of time domain is multiplexing, difference is only that the time-domain OFDM symbol position mapped adjusts, thus can adapt to the situation that DwPTS is configured to 10 OFDM symbol.Still defining the two groups of layers carrying out code division multiplexing is g ₁and g ₂.Then corresponding time-frequency domain position is:

g ₁：

g ₂：

Fig. 9-g, compared with 9-c, employs higher demodulation reference mark density, and still adopting between the first time slot is with each layer is still the code division multiplexing mode of CDM-T between two, and the and time slot adopts the code division multiplexing mode of CDM-F.The layer carrying out code division multiplexing is divided into 1 group, is then divided into 4 groups according to maximum layer number, is designated as respectively: g ₁, g ₂, g ₃, g ₄.Such as g ₁: { 1,2} layer, g ₁: { 3,4} layer, g ₁: { 5,6} layer, g ₁: { 7,8} layer.The time-frequency domain position relationship of each layer is:

g ₁：

g ₂：

g ₃：

g ₄：

In Fig. 9-h, each layer all adopts the mode of CDM-F, and the packet mode in 9-h is identical with 9-a, and time different from 9-a, in the mode that Fig. 9-h illustrates, at the first time slot, each layer carrying out code division multiplexing carries out at frequency domain.In mode shown in 9-h, identical in the position of the second time slot with 9-a in the time-frequency domain position of the second time slot, with reference to above to the location expression of 9-a at the second time slot, only 9-h can be described in the position of the first time slot here.At the first time slot, the time-frequency domain position of its correspondence is:

g ₁：

g ₂：

g ₃：

g ₄：

Fig. 9-e and 9-f gives mapping pattern when DwPTS is configured to 9 OFDM symbol, and pattern is equally applicable to be configured to 10,11, during 12 OFDM symbol as DwPTS.Wherein Fig. 9-e be based on 9-a signal be configured to 11 or 12 OFDM symbol time, on the basis of described scheme, directly remove last two-way, concrete mapping position can be obtained to last two-way is directly removed on the basis of the mode described by 9-a based on above-mentioned, concurrent multiplexing mode, with reference to the description to 9-a, repeats no more here.

The mode illustrated in 9-d of scheme given by Fig. 9-f is configured to the at time-domain position, and { pattern of 3,4,6,7}, also repeats no more here, and multiplex mode and frequency domain position are with reference to 9-b and 9-d.

2, extended cyclic prefix situation

DMRS pattern (when number of layers is 5 ~ 8) when different DwPTS configures under Figure 11 shows and expands CP, wherein Figure 10-a, the corresponding normal sub-frames of 10-b, 10-c, Figure 10-d, 10-e, the correspondence of 10-f is configured to 9, pattern during 10 OFDM symbol, Figure 10-g, 10-h, 10-i correspondence is configured to pattern during 8 OFDM symbol.Under Figure 11 gives extended cyclic prefix situation, the demodulation reference mark mapping method when rank5 ~ 8, wherein Figure 10-a, 10-b, 10-c are the mapping mode of normal sub-frames.Figure 10-d, 10-e, 10-f are the mapping mode of DwPTS when being configured to 9 or 10 OFDM symbol, Figure 10-g, and 10-h, 10-i are the mapping mode schematic diagram of DwPTS when being configured to 8 OFDM symbol.

When normal sub-frames, 10-a gives one and adopts CDM-F completely, and adopt code length to be that the spreading code of 2 is at the demodulation reference mark mapping method of frequency domain code division multiplexing, Figure 10-b gives and is entirely CDM-T, adopt code length be 4 spreading code in time domain 4 OFDM symbol, carry out the demodulation reference mark mapping method of orthogonal multiplex, 10-c gives and is entirely CDM-T, and the spreading code that employing code length is 2 carries out the reference symbol mapping method of orthogonal multiplex in adjacent 2 OFDM symbol of time domain.

In Figure 10-a, and in Figure 10-c, adopt code length to be the spreading code of 2, carry out code division multiplexing between two between layer, be namely divided into four groups, be designated as g respectively ₁, g ₂, g ₃, g ₄, often group comprises 2 layers, carries out code division multiplexing between the layer in group, adopts frequency division multiplexing, such as g between the layer of different group ₁: { 1,2} layer, g ₁: { 3,4} layer, g ₁: { 5,6} layer, g ₁: { 7,8} layer.

Wherein, in the mapping mode schematic diagram shown in Figure 10-a, layer time-frequency domain position in whole subframe of each group correspondence represents with x and y respectively, and wherein x represents shared time-domain OFDM symbol position, and y represents the sub-carrier positions in a PRB.Then the time-frequency domain positional representation of the layer that each group is corresponding is:

g ₁：

g ₂：

g ₃：

g ₄：

Mapping mode shown in Figure 10-c is the mode of CDM-T, and the time-frequency domain position of each group correspondence represents with x and y equally respectively, and wherein x represents shared time-domain OFDM symbol position, and y represents the sub-carrier positions in a PRB.Then the time-frequency domain positional representation of the layer that each group is corresponding is:

g ₁：

g ₂：

g ₃：

g ₄：

Mapping method shown in Figure 10-b, the code length adopted is 4, is now divided into two groups of groups, is designated as g respectively ₁, g ₂, wherein often group comprises 4 layers and carries out code division multiplexing, and the layer between group carries out frequency division multiplexing.Each group of corresponding time-frequency domain position represents with x and y equally respectively, and wherein x represents shared time-domain OFDM symbol position, and y represents the sub-carrier positions in a PRB.Then the time-frequency domain positional representation of the layer that each group is corresponding is:

g ₁：

g ₂：

Mapping mode when DwPTS is configured to 9 or 10 OFDM symbol, can adopt Figure 10-d, and any one in the various modes that 10-e, 10-f illustrate carries out the mapping of demodulation reference mark.Wherein the mode illustrated of Figure 10-d is CDM-F mode completely, adopt code length be the spreading code of 2 to the two two-layer code division multiplexings that carry out, be adjust based on the time-domain position of Figure 10-a; Figure 10-e is the method for CDM-T, and is the orthogonal code of 4 in employing code length, and time domain 4 symbols carry out orthogonal multiplex to the layer carrying out code division multiplexing; Figure 10-f be CDM-T and CDM-F combine multiplex mode, and adopt code length be 2 orthogonal code code division multiplexing is between two carried out to layer.

In Figure 10-d, the mapping mode of its correspondence is the adjustment of the time-domain position of the mode that Figure 10-a illustrates, multiplex mode and frequency domain position keep with constant to the description part of the mode of 10-a institute time domain.For avoiding repeating to discuss, only the adjustment belonging to position being described here, frequency domain position and multiplex mode are repeated no more.In the mode that Figure 10-d illustrates, the time-domain position of each group correspondence is adjusted to:

G ₁: time-domain position: x={x ₁, x ₂}={ 3,9} or { 4,9}

G ₂: time-domain position: x={x ₁, x ₂}={ 3,9} or { 4,9}

G ₃: time-domain position: x={x ₁}={ 6}

G ₄: time-domain position: x={x ₁}={ 6}

The multiplex mode that Figure 10-e adopts is identical with the mode that Figure 10-b describes, it is a position adjustment based on Figure 10-b, object avoids when DwPTS is configured to 9 or 10 OFDM symbol, the symbol of transmission DMRS conflicts with UpPTS or GP, the multiplex mode that Figure 10-e adopts is identical with Figure 10-b with frequency domain position, here repeat no more, same is described the adjustment position of time-domain position.Under the mapping mode that Figure 10-e illustrates, the time-domain position based on Figure 10-b is adjusted to:

G ₁, g ₂: time-domain position: x={ [x ₁, x ₂, x ₃, x ₄]={ 3,5,6,9}

In Figure 10-f, employing be the multiplex mode that CDM-T and CDM-F combines, wherein at the first time slot, the layer carrying out code division multiplexing adopts the multiplex mode of CDM-T; At the second time slot, the layer carrying out code division multiplexing adopts the multiplex mode of CDM-F.Between each layer between two adopt adopt code length be 2 orthogonal code carry out code division multiplexing.The layer that will carry out code division multiplexing is divided into 1 group, be then divided into 4 groups according to maximum layer number, be designated as respectively: g ₁, g ₂, g ₃, g ₄.Such as g ₁: { 1,2} layer, g ₁: { 3,4} layer, g ₁: { 5,6} layer, g ₁: { 7,8} layer.The time-frequency domain position relationship of each layer is:

g ₁：

g ₂：

g ₃：

g ₄：

Another each layer is given in a RB in Figure 10-J, the pattern of even density distribution, under the mode illustrated in the drawings, 5th, 6 OFDM symbol adopt the mode of CDM-T multiplexing, in the 3rd and the 9th OFDM symbol, adopt the mode of CDM-F multiplexing, equally, the mode illustrated in figure be each layer correspondence reference symbol between adopt between two code length be 2 orthogonal code carry out code division multiplexing, multiplexing by the mode of frequency division between group.The layer that will carry out code division multiplexing is divided into 1 group, be then divided into 4 groups according to maximum layer number, be designated as respectively: g ₁, g ₂, g ₃, g ₄.Shared by the reference symbol of now each layer correspondence, the time-frequency domain position of RE is (time-domain position here describes according to the index of OFDM symbol in a subframe):

g ₁：

g ₂：

g ₃：

g ₄：

Mapping mode when DwPTS is configured to 8 OFDM symbol, can adopt Figure 10-g, and any one in the various modes that 10-h, 10-i illustrate carries out the mapping of demodulation reference mark.Wherein 10-h removes last two-way based on 10-c to obtain, and remaining mapping position, with reference to the description part to 10-c, also no longer repeats here.Here main 10-g, 10-i to be described.

Figure 10-g is the mode of CDM-F, OFDM symbol position shared by it is the 3rd and the 6th or the 5th OFDM symbol, illustrate according in figure, adopt between two between the reference symbol of each layer correspondence code length be 2 orthogonal code carry out code division multiplexing, multiplexing by the mode of frequency division between group.The layer that will carry out code division multiplexing is divided into 1 group, be then divided into 4 groups according to maximum layer number, be designated as respectively: g ₁, g ₂, g ₃, g ₄.Shared by the reference symbol of now each layer correspondence, the time-frequency domain position of RE is (time-domain position here describes according to the index of OFDM symbol in a subframe):

g ₁：

g ₂：

g ₃：

g ₄：

In 10-i, carry out code division multiplexing layer adopt CDM-TF, and adopt between two between layer code length be 2 orthogonal code carry out code division multiplexing.In the 3rd OFDM symbol, wherein adopt the multiplex mode of CDM-F, the 5th, 6 OFDM symbol adopts CDM-T multiplexing, and now concrete time-frequency domain position relationship is:

g ₁：

g ₂：

g ₃：

g ₄：

It should be noted that, in the various mapping modes described in preferred embodiment one to preferred embodiment three, the pattern in DwPTS situation also can be suitable in normal sub-frames.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

As can be seen from the above description, present invention achieves following technique effect:

Obviously, those skilled in the art should be understood that, above-mentioned of the present invention each module or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on network that multiple calculation element forms, alternatively, they can realize with the executable program code of calculation element, thus, they can be stored and be performed by calculation element in the storage device, or they are made into each integrated circuit modules respectively, or the multiple module in them or step are made into single integrated circuit module to realize.Like this, the present invention is not restricted to any specific hardware and software combination.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a mapping method for reference symbol, is characterized in that, described method comprises:

At first time slot of subframe, carry out taking same subcarrier between the same layer of code division multiplexing or reference symbol corresponding to same port, and carry out time domain code division multiplexing on the adjacent or close OFDM symbol that described subcarrier is corresponding;

At second time slot of described subframe, carry out taking same OFDM symbol between the same layer of code division multiplexing or reference symbol corresponding to same port, and at adjacent or close multiple subcarriers enterprising line frequency territory code division multiplexing of described OFDM symbol.

2. method according to claim 1, is characterized in that, in normal cyclic prefix situation, carries out time domain code division multiplexing carry out time division multiplexing in one of following OFDM symbol position at described first time slot:

In described first time slot the 3rd, 4 OFDM symbols;

In described first time slot the 6th, 7 OFDM symbols;

In described first time slot the 4th, 6 OFDM symbols.

3. method according to claim 1, is characterized in that, in normal cyclic prefix situation, for described second time slot, described method also comprises:

When layer/port number is 1 or 2, with the 3rd or the 4th OFDM symbol of described second time slot;

When layer/port number is greater than 2, with in the 3rd and the 4th OFDM symbol of described second time slot one of at least.

4. method according to claim 1, is characterized in that, in extended cyclic prefix situation, carrying out the multiplexing corresponding OFDM symbol position of time domain code division multiplexing at described first time slot is:

In described first time slot the 3rd, 5 OFDM symbols, or

In described first time slot the 5th, 6 OFDM symbols.

5. method according to claim 1, is characterized in that, in extended cyclic prefix situation, carries out at described second time slot the 3rd OFDM symbol that multiplexing the used OFDM symbol of frequency domain code division multiplexing is second time slot.

6. method according to any one of claim 1 to 5, it is characterized in that, carrying out on the multiplexing OFDM symbol of time domain code division multiplexing, frequency domain position is the 1st in current resource block RB, 6th and the 11st subcarrier, or the 2nd, 6,10 subcarriers or the 1st, 4,7,10 subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

7. method according to any one of claim 1 to 5, is characterized in that, carrying out on the multiplexing OFDM symbol of frequency domain code division multiplexing, frequency domain position is { 1,2} subcarrier, { 6,7} subcarriers, { 11,12} subcarriers; Or 2,3} subcarriers or 6,7} subcarriers or 10,11} subcarriers or 1,2}, 3,4}, 5,6}, 7,8}, 9,10}, { 11,12} subcarriers, or the cyclic shift of above-mentioned position frequency domain in a RB.

8. method according to any one of claim 1 to 5, is characterized in that, when design for demodulation reference mark, each road reference symbol is corresponding with floor; During for witness mark symbol, each road reference symbol is corresponding with antenna port.